In the past, apparatus employed for de-aeration or vacuum packing of flowable materials, particularly of a dusty composition, employed rarefaction or suction processes and included structure which was fitted peripherally around an opening in a bag or the like to filled which was then clamped to the filler spout of a filling machine. Many of these prior art devices were either incompatible with the particular materials being packaged for one reason or another, or did not completely de-aerate the materials being packaged, and seldom achieved true vacuum packing of the materials.
Typical apparatus previously employed for vacuum packing flowable materials into an open mouth type bag include a filling station provided with weighing or proportioning mechanism for measuring the amount of material being dispensed into the bag; a dispensing hopper provided with a cylindrical or oval spout about which an operator fits the mouth of an empty bag; and, a system of grips which secure the periphery of the bag defining the opening therein to the filling spout. These prior art devices are satisfactory for holding the bag in a proper position around the spout during filling but are undesirable from the standpoint that potentially harmful, pollutive materials are allowed to escape from the bag during, or shortly after, the filling process, due to incomplete sealing of the bag around the filler spout.
The filling operations which involve a flowable material that is particularly dusty in nature poses an even greater problem to be overcome, since, during high speed operations, a considerable amount of dusty material tends to be forced out of the bag opening which finds its way between the bag and the dispensing spout, thereby making it difficult to hermetically seal the bag around the spout in a manner to prevent emanation of the dusty materials into the ambient atmosphere. Moreover, prior art devices of the type described above are often provided with a dispensing spout which is exposed to the open air when a filled bag is removed therefrom, thus permitting a certain amount of dusty material remaining within the spout to escape into the atmosphere while a portion of such material which clings to the sides of the spout drop off when the bag is removed.
The present invention eliminates each of the above mentioned deficiencies inherent in prior art apparatus. According to the present invention, apparatus is provided for securing the bag on a filler spout in a manner to preclude escape of dusty materials from either the bag or the spout both during and after the filling operation in order to eliminate escape of filler materials into the atmosphere which may have deleterious effects either on the environment or human operators. The apparatus is particularly adapted for use with bags or packages provided with porous disks or openings in the sides thereof which may be coupled with an air suction system forming part of the apparatus which draws out dusty materials suspended in the air within the bag during the filling process. Subsequent to the filling process, the porous disks may be sealed by means of varnish, glue or an adhesive label applied thereto. The apparatus includes a spout provided with a lower flexible portion and a pair of opposed, shiftable hinged plates on opposite sides of the spout which have the opposite extremeties thereof connected to each other by hinges which allow shifting the plates toward and away from each other in a manner to selectively destort the spout in order to control the flow of material therethrough. A bag or the like is sleeved around the hinged plates while shiftable structure is provided including grip members for holding and tightly sealing the bag to the hinged plates.